This weekend (November 22 and 23), the annual “Super Megafest” event returns to the greater-Boston area with a loaded lineup of celebrity guests. From Star Trek: The Next Generation; Marina Sirtis (Deanna Troi), Denise Crosby (Tasha Yar), Dwight Schultz (Reginald Barclay) and Lee Arenberg (Prak, Bok) will be on hand all weekend, signing autographs and taking photos with fans, at scheduled times.